rad help pt.2

hey guys i got a 2000 civic sir (1.6 DOHC VTEC)

i changed the rad and thermostat last week it was all good ten yesterday the temp went up and i checked under the hood, the hoses were FULL of pressure and the upper one was HOT and the lower one was COLD...is that a bad thermostat? is there a way to check if it is bad?
any help would be appreciated. thanks

and thanks for all the help last week

gary

The best way to check the thermostat is to remove it and simulate the conditions in water .boil the water to the temp it's rated to open at (thermostat).see if the wax pellet moves the spring.and also if you already changed the items make sure you bleed the system properly with the heat on .if that doesn't work . you might possilbly have a water pump issue.